It has hereto been common practice to use gas shocks to assist in the opening or lifting of large or tall enclosures. This was typically accomplished using one of two methods. In the first method, the gas shocks were under-sized to allow the user to still be able to close the enclosure, while still providing a degree of assistance. In the second method, the travel of the enclosure is limited to forty five degrees. This permits the gas shocks to be sized correctly, but prevents the enclosure from being fully opened unless the gas shocks are uninstalled. Both of these options require the use of an end restraint to prevent the hood from over-extending the gas shock and thereby shortening its life.
The design of assist mechanisms that utilize gas shocks for enclosures that are tall presents unique problems. While the gas shocks will successfully lift the enclosure, in the full open position (approximately ninety degrees from horizontal), the center of gravity is located behind the hinge. As a consequence thereof, in order to close the enclosure, the operator is required to not only overcome the weight of the enclosure, but also the strength of the gas shocks. This in turn limits the strength of the shock that can be used, as a stronger shock would severely hamper an operator's ability to close the enclosure. Since the strength of the gas shock is limited, the amount of assistance that can be supplied in opening the enclosure is also limited.
The alternative is to limit the travel of the enclosure such that the gas shocks do not push the center of gravity of the enclosure past the hinge. In some applications, this only allows for the enclosure to be opened about forty five degrees instead of ninety degrees, and therefore limits or restricts the access which can be gained through the enclosure. Some applications have allowed the gas shocks to be removed as a part of operating the enclosure when it is necessary to open it beyond the travel of the gas shocks.
Additionally, it has heretofore been necessary to take great care to prevent the gas shocks from over-extending, such as the utilization of an end-stop. If the gas shocks are permitted to fully extend before the endstop is engaged, the weight of the enclosure will tend to over-extend the shocks and thereby greatly reduce their useful life.
The present invention is directed toward overcoming one or more of the problems set forth above.